Au–Ag assembled on silica nanoprobes for visual semiquantitative detection of prostate-specific antigen

Abstract

Background Blood prostate-specific antigen (PSA) levels are widely used as diagnostic biomarkers for prostate cancer. Lateral-flow immunoassay (LFIA)-based PSA detection can overcome the limitations associated with other methods. LFIAbased PSA detection in clinical samples enables prognosis and early diagnosis owing to the use of high-performance signal reporters. Results Here, a semiquantitative LFIA platform for PSA detection in blood was developed using Au–Ag nanoparticles (NPs) assembled on silica NPs (SiO2@Au–Ag NPs) that served as signal reporters. Synthesized SiO2@Au–Ag NPs exhibited a high absorbance at a wide wavelength range (400–800 nm), with a high scattering on nitrocellulose membrane test strips. In LFIA, the color intensity of the test line on the test strip differed depending on the PSA concentration (0.30–10.00 ng/mL), and bands for the test line on the test strip could be used as a standard. When clinical samples were assessed using this LFIA, a visual test line with particular color intensity observed on the test strip enabled the early diagnosis and prognosis of patients with prostate cancer based on PSA detection. In addition, the relative standard deviation of reproducibility was 1.41%, indicating high reproducibility, and the signal reporter showed good stability for 10 days. Conclusion These characteristics of the signal reporter demonstrated the reliability of the LFIA platform for PSA detection, suggesting potential applications in clinical sample analysis.

Quantitative assessment of AD markers using naked eyes: point-of-care testing with paper-based lateral flow immunoassay

“…The unlabeled AuNPs were aggregated under the action of 10% NaCl. On the contrary, only when the amount of antibody reaches or slightly exceeds the stable amount, the AuNPs can remain stable [ 60 , 61 ].…”

Recent Advances in Silica-Nanomaterial-Assisted Lateral Flow Assay

“…In LFAs, silica nanomaterials usually work as a protective shell to stabilize label materials, a carrier to enrich label materials for signal amplification or the colored label itself. Reprinted with permission from References [ 20 , 21 , 22 , 23 ].…”

Lateral Flow Immunoassay with Quantum-Dot-Embedded Silica Nanoparticles for Prostate-Specific Antigen Detection

“…LFIA is used as a point-of-care test with the advantages of fast turnaround time, low cost, and feasibility [ 18 , 19 , 20 ]. Various types of nanomaterials have been used as detection probes for LFIAs depending on the application [ 21 , 22 , 23 ]. Metal nanoparticles (NPs), such as those composed of gold (Au), silver (Ag), and alloy metals, have been used for colorimetric detection with the naked eye [ 21 , 22 , 24 , 25 ].…”

“…Various types of nanomaterials have been used as detection probes for LFIAs depending on the application [ 21 , 22 , 23 ]. Metal nanoparticles (NPs), such as those composed of gold (Au), silver (Ag), and alloy metals, have been used for colorimetric detection with the naked eye [ 21 , 22 , 24 , 25 ]. Well-designed fluorescent NPs have been used for more sensitive and accurate analysis than colorimetric detection [ 26 , 27 ].…”